AdsoYo

iTrader: (1)

I just installed a ram air system on my car which has the MAF sitting right over the water pump. I put my new pcmforless PCM in at the same time while I had the hood up. I drove around fine for about 40 miles when all of a sudden it felt like the car hit the brakes. I didn't think anything of it until it happened again a few minutes later. I cycled through the scanmaster readings and saw it was running richer than it had been right after the PCM finished its "learning mode". It also showed a DTC 48 - MAF circuit fault. I tried some hard accelerations and kept getting misses.

After 10 miles of granny driving I cycled through the scanmaster readings again and through my glances caught these:

MAF - 467
LBL - 144
RBL - 137
SP - 44

Yes, the MAF was reading 467 when it should be around 15 - 20 for a light cruise. It was running lean as you can see.

When I got back to my place, I let it idle and checked again. The readings were the same and the car kept approaching the brink of dying. It almost sounded like I had the biggest cam in the world. I checked the MAF right away and saw that the corner was touching the coolant hose on the water pump. I rotated the MAF as much as I could but I don't have the wire extension so it's maybe 1/2" - 1" off the hose now.

This was 3 hours ago, I just started it again and it ran fine but still showed the dtc 48 so I unplugged the battery and will check if it shows back up in about 20 minutes.

Did I fry my MAF? What do you guys think?

ProgGod

just tune for speed density mode.. i hollowed out mine

AdsoYo

iTrader: (1)

Car works fine now. Moral of the story: don't let your water pump boil your MAF.

poconojoe

iTrader: (43)

You need to understand how the MAF works. It has a wire in it that the air going across it cools. It uses an electric current to try to keep the wire at a set temp. It measres the ampunt of current used and determines the amount of aire flow. If there is an external source of heat, the MAF can't properly control the wire temp and gives false readings.

AdsoYo

iTrader: (1)

Well, I did a WOT run and it happened again, miss with a DTC 48. I really don't want to replace the MAF.

AdsoYo

iTrader: (1)

Drove around with scanmaster on MAF and the misses I feel while driving are the MAF cutting on and off. It will go between 20 (or whatever, depends on the throttle) and 461, not 467. After some searching I found that this means it's in speed density mode and there is basically a severed connection between the maf and pcm.

I tested the pcm wire for the maf which should read 12v and got 11.8v, close enough so the wire is good. I'm gonna swap my old PCM back in and see what that does.

AdsoYo

iTrader: (1)

Took a look at the MAF and this is what I saw. The ram air is a tight fit, but I didn't know the air box was shoved up against the screen. Could this be enough to screw up the MAF? The sensors look OK.

awd2rwd

iTrader: (17)

Check this out...when ever i was driving my 383ci C5 i would do wot pulls and get reduced engine power and codes on my dic....turns out my the wires running from my maf up near my throttle body were being jerked on when my motor flexed under hard acceleration and therefore giving my maf a faulty connection...just fyi

AdsoYo

iTrader: (1)

Well, it's been a looong ***** fudgin' day trying to fix this thing. I drove around in speed density for a while and it ran like a dream. LBL and RBL were hovering around 128 the whole time, I almost chucked the MAF. Got some MAF cleaner and a q-tip and gave her a bath. Seems to be running fine now, if a little on the rich side. We'll see.

ProgGod

Why even use the maf, speed density is the way to go

lt170chevelle

iTrader: (2)

if it starts acting up again just start it up and wiggle the maf wires ..probally have a bad connection or short.